Objective To investigate the preparation and application of a kind of discoloration dilution suitable for clinical application in anti-HBc assay.Methods Choose one acid-base indicator from the neutral-near indicators to compound a discoloration dilution of needed concentration. Then use colorless and discoloration dilution to detect the anti-HBc simultaneously.Results Anti-HBc positive or negative results were coincident with that detected with colorless and discoloration dilution. The linear correlation of them was very good (r=0.995,P0.05).Conclusion Discoloration dilution in clinical use can greatly increase the reliability and efficiency of the experiment,effectively avoid misdiagnosis and missed diagnosis.